This is possible as libfaad no longer has patented functionality based on
BUILD_PATENTED.
AAC is a very popular format, so it makes sense to have some kind of
version included.
The ffmpeg package does not provide and cannot provide AAC decoding
without BUILD_PATENTED, therefore enabled FAAD for all variants.
Signed-off-by: Rosen Penev <rosenp@gmail.com>